EX-4.1





 Exhibit 4.1 
  





 
 NUMBER 
SHARES 
INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE 
SEE REVERSE FOR CERTAIN DEFINITIONS

COMMON STOCK 
CUSIP 162818 10 8 
This Certifies That: 
SPECIMEN - NOT NEGOTIABLE 
is The owner of 
FULLY PAID AND NON-ASSESSABLE SHARES
OF COMMON STOCK OF $0.0001 PAR VALUE EACH OF 
Checkmate Pharmaceuticals, Inc.

transferable on the books of the Corporation by the holder thereof in person or by duly authorized attorney upon surrender of this certificate duly endorsed or
assigned. This certificate and the shares represented hereby are subject to the laws of the State of Delaware, and to the Certificate of Incorporation and Bylaws of the Corporation, as now or hereafter amended. 
This certificate is not valid until countersigned by the Transfer Agent. 
WITNESS the facsimile
seal of the Corporation and the facsimile signatures of its duly authorized officers. 
COUNTERSIGNED: 
BROADRIDGE CORPORATE ISSUER SOLUTIONS, INC. 
TRANSFER AGENT 
DATED: 
BY:

AUTHORIZED SIGNATURE 
SPECIMEN 
NOT NEGOTIABLE 
CHIEF BUSINESS OFFICER 
PRESIDENT AND CHIEF EXECUTIVE OFFICER 












 The following abbreviations, when used in the inscription on the face of this
certificate, shall be construed as though they were written out in full according to applicable laws or regulations: 
  

											
	TEN COM	 	-	 	as tenants in common	  	UNIF GIFT MIN ACT -	 	                          Custodian    
                        
	TEN ENT	 	-	 	as tenants by the entireties	  		 	(Cust)	  	(Minor)
	JT TEN	 	-	 	as joint tenants with right of	  		 	under Uniform Gifts to Minors
		 		 	survivorship and not as tenants	  		 	Act                                  
                                
		 		 	in common	  		 	(State)

 Additional abbreviations may also be used though not in the above list. 

For Value
Received,                                       
          hereby sell, assign and transfer unto 
  

			
	PLEASE INSERT SOCIAL SECURITY OR OTHER	  	
	 IDENTIFYING NUMBER OF ASSIGNEE
  
	  	
	    	  	

  

			
	    	 	 
	(PLEASE PRINT OR TYPE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)	 	
		
	    	 	 
		
	    	 	 
		
	    	 	Shares
	of the stock represented by the within Certificate, and do hereby irrevocably constitute and appoint	 	
		
	 	 	Attorney
	to transfer the said stock on the books of the within named Corporation with full power of substitution in the premises.	 	

  

			
	
Dated                 
                                         
                                   
	 	

  

			
		  	NOTICE: THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF THE CERTIFICATE IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE
WHATSOEVER.
	Signature(s) Guaranteed	  	 

  

					
	By	 	                                 
                                         
                                    	 	 
	The Signature(s) must be guaranteed by an eligible guarantor institution (Banks, Stockbrokers, Savings and Loan Associations and Credit Unions with membership in an approved Signature
Guarantee Medallion Program), pursuant to SEC Rule 17Ad-15.	 	

 THE CORPORATION WILL FURNISH TO ANY STOCKHOLDER, UPON REQUEST AND WITHOUT CHARGE, A FULL STATEMENT OF THE DESIGNATIONS,
RELATIVE RIGHTS, PREFERENCES AND LIMITATIONS OF THE SHARES OF EACH CLASS AND SERIES AUTHORIZED TO BE ISSUED, SO FAR AS THE SAME HAVE BEEN DETERMINED, AND OF THE AUTHORITY, IF ANY, OF THE BOARD TO DIVIDE THE SHARES INTO CLASSES OR SERIES AND TO
DETERMINE AND CHANGE THE RELATIVE RIGHTS, PREFERENCES AND LIMITATIONS OF ANY CLASS OR SERIES. SUCH REQUEST MAY BE MADE TO THE SECRETARY OF THE CORPORATION OR TO THE TRANSFER AGENT NAMED ON THIS CERTIFICATE. 

 
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